Generally, a fuel supply apparatus of a vehicle, which is an apparatus transferring required fuel to an engine, includes a fuel tank storing the fuel therein and a fuel pump module supplying the fuel in the fuel tank to the engine or a fuel injection apparatus and is configured so that fuel remaining after being used in the engine is returned to the fuel pump module or an inner portion of the fuel tank.
Here, the fuel tank may be formed in a saddle type in which a central portion of a lower portion thereof is inwardly concave in order to secure a space due to a configuration of a connection shaft connecting an engine and a rear wheel shaft to each other in the case of a four-wheel driving vehicle.
Further, in the case in which a fuel pump module mounted in the saddle type of fuel tank is used, since a space of the fuel tank is divided from a specific height or less, the fuel pump module should be configured so that all fuel in the divided space may be transmitted to the engine.
As shown in FIG. 1, the fuel pump module 10 for the saddle type of fuel tank as described above is configured to include a flange assembly 20 mounted on a first space part 51 of the saddle type of fuel tank 50 in which the first space part 51 and a second space part 52 are formed and a reservoir body assembly 40 connected to a lower portion of the flange assembly 20 by a guide rod 30, wherein the reservoir body assembly 40 includes a reservoir body 41 having a hollow part 41a formed in a lower surface thereof so that fuel is introduced; a fuel pump 42 sucking fuel in the reservoir body 41 to transmit the fuel to an engine 60; a first jet pump 43 formed so that fuel in the first space part 51 of the fuel tank 50 is sucked through the hollow part 41a while a portion of fuel that is not transmitted to the engine 60 or returned fuel passing through the engine moves; a diffuser type of first guide tube 45 standing in a direction perpendicular to the reservoir body 41 to transmit the fuel passing through the first jet pump 43 or the fuel sucked through the hollow part 41a into the reservoir body 41; a second jet pump 44 formed so that fuel in the second space part 52 of the fuel tank 50 is sucked through a transfer line 48 while the fuel passing through the first jet pump 43 moves; a diffuser type of second guide tube 46 standing in the direction perpendicular to the reservoir body 41 to transmit the fuel passing through the second jet pump 44 or the fuel sucked through the transfer line 48 into the reservoir body 41; and a guide part 47 formed to face the second guide tube 46 at an upper portion of the second guide tube 46 to guide the fuel discharged from the second guide tube 46 to the second guide tube 46.
As described above, the fuel pump module 10 is mounted with the first space part 51, the transfer line is connected to a lower portion of the second guide tube 46 to suck the fluid in the second space part 52, and the fuel in the first space part 51 and the second space part 52 is simultaneously sucked while the fuel passes through the first jet pump 43 and the second jet pump 44, such that the fuel is filled in the reservoir body 41, thereby making it possible to transmit the fuel to the engine through the fuel pump 42.
The fuel pump module 10 is configured so that it has the transfer line 48 connected thereto, thereby making it possible to simultaneously suck the fuel received in the first space part 51 and the second space part 52 of the saddle type of fuel tank 50. However, in a state in which the fuel is present at a specific height or less of the fuel tank 50 and an operation of the fuel pump 42 stops, the fuel in the reservoir body 41 is discharged toward the fuel tank 50, such that air rather than the fuel is filled in the second guide tube 46.
In this case, when the fuel pump 42 operates, the fuel pump 42 first sucks the fuel in the first space part 51 of the fuel tank in which the fuel pump module 10 is mounted and may suck the fuel in the second space part 52 together with the fuel in the first space part 51 only after the fuel is filled in the second guide tube 46 after the passage of a predetermined time.
That is, the fuel in the first space part 51 is first sucked and used, and the fuel in the second space part 52 remains, such that the fuel in the second space part 52 may not be used.
In order to solve this phenomenon, the fuel jetted from the second jet pump 44 has been introduced into the second guide tube 46 by the guide part 47 formed at the upper portion of the second guide tube 46. However, an amount of introduced fuel is small, such that the fuel in the second space part 52 of the fuel tank 50 may not be rapidly transmitted.
Therefore, the fuel in the first space part and the second space part of the fuel tank may not be appropriately sucked, such that the fuel may not be stably supplied.